Boltless gatling gun mechanism



Sept. 19, 1967 E. J. FAGERsTRoM 3,342,105

BOLTLESS GATLNG' GUN MEGHANISM Filed Jan. 28, 1966 l y 4 sheets-sheet 1 www la o gv WN. MN

3 WHL.

SePf- 19, 1967 E. J. FAGERSTROM 3,342,105

BOLTLESS GATLING GUN MECHANISM Filed Jan. 28, 1966 4 Sheets-Sheet 2 E n 1N VENTOR,

Sept. 19, 1967 E.J. FAGERSTROM 3,342,105

BOLTLESS GATLING GUN MECHANISM Filed Jan. 28, 1966 4 Sheets-Sheet 5 INVENTOR. f. A wffesfo/w United States Patent Office 3,342,105 Patented Sept. 19, 1967 3,342,105 BOLTLESS GATLING GUN MECHANISM Emile J. Fagerstrom, 213 Baker Ave. NW., Fort Walton Beach, Fla. 32548 Filed Jan. 28, 1966, Ser. No. 523,805 7 Claims. (Cl. 89-12) ABSTRACT OF THE DISCLOSURE A Gatling type machine gun having the barrels thereof pivoted at their muzzle ends for inward and outward radial adjustmentl of their breech ends about a common central axis during rotation thereof and cam means at the breech or rear ends ofthe barrels for camming the breech ends of the barrels radially inwardly toward the center ofrotation of the barrels, into firing position during rotation of the barrels laround said axis, and then outwardlyqinto shell or round extracting and round loading and ramming positions, and a common rotor for rotating the barrels around said center comprising means -for backing up the rounds in the breech ends of the barrels in the tiring position during the vfiring cycle.

The invention described `herein may be manufactured and used` by or for the United States Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to ordnance, and more particularly to machine` guns of the class known as Gatling guns, having for an object the provision of a simplified rotatable multiple barrel machine gun which eliminates the usual gun breech bolt and locking assemblies and most of the related conventional moving gun parts usually employed in the Gatling gun types of machine guns.

`A further object of the invention is the provision of a Gatling type machine gun in which the slidable breech block assemblies are eliminated by pivoting each of the barrels at its muzzle end and the provision of cam means at `the breech or rear end whereby as the barrels are rotated each barrel may be cammed radially inward for the firing cycle and outward radially to facilitate feeding, ramming, and shell extraction cycles, utilizing the barrel rotor for rotating the barrels, to back up the rounds during the `firing cycle.

, A further object of the `invention is the provision of a gun `employing the Gatling `gun principles in which the chambered end of each barrel containing the chambered `round is `automatically cammed radially inward during rotation of the barrels around a common axis so that the butt end of each round is supported by the main rotor for the barrels during firing, and the barrels are cammed radially outward to radially displace the spent round from its backed up relation with the main rotor into engagement with the shell ejector means, including camniing means `for reciprocating the ejector and round ramming unit back` and forth incident to rotation of the rotor and barrels about the common central axis.

Afurther object is the provision of a machine gun of the Gatling type which eliminates the `slidable locking breech bolts and associated parts, in which the feed or ram strokes take place over approximately 180 of the rotation of the barrels and rotor and is accomplished by the rounds riding in grooves in a spinning rotor which rotates with the barrels while the rounds are cammed forward into the round receiving chambers in the barrels by a cam actuated rammer-ejector unit to chamber the rounds in the barrels, and the barrels are then cammed inward radially to disengage the rammer-ejector unit about 30 'before 'battery to Amove the chambered rounds radially inward into rear end supporting relation with rotor during firing, and includes spring projected firing pin means for each barrel carried by the rotor for alignment with the primer of each round when the 'barrel is cammed inward radially to its firing position also including xed cam means on the main housing of the gun for successively retracting and releasing the firing pins for each barrel as each barrel is rotated and cammed inwardly into rotor backed up firing position.

A further object is the provision of stationary camming means carried by the gun casing or frame for camming the breech ends of the barrels radially inwardly into liring position and outwardly into spent round ejecting and fresh round ramming positions during rotation of the barrels around their fixed common axis, in which the feed and ram strokes for each barrel take place over approximately of rotation of each barrel around the central axis of the gun and the round in each barrel is chambered, and each barrel is cammed inward radially into firing position approximately 30 before firing.

AOther objects and advantages of the invention will become apparent from the lfollowing description and accompanying drawings in which like reference characters refer to like parts in the several figures.

Drawings of the barrels between the rear or breech end and theV muzzle end of the gun being broken away and omitted to foreshorten the view, the gun mounting means or stand stand and round feeding means, and means for ejecting or removing the spent shells from the gun being conventional, and therefore also omitted.

FIG. 2 is a fragmentary top plan view of the rear oi breech end of gun as shown in FIG. 1 also with the mounting means omitted.

FIG. 3 is a 4fragmentary side elevation View of the breech end of the gun with the mounting means omitted and looking in the same direction as in FIG. 1.

FIG. 4 is a somewhat schematic transverse sectional lView taken about on the plane indicated by line 4 4 in FIG. 1 and looking in the direction of the arrows.

FIG. 5 is a fragmentary transverse sectional view taken about on line 5 5 of FIG. 1, looking in the direction of the arrows, more clearly showing the slotted rotary barrel locking plate or disc which prevents relative longitudinal thrust movement of the barrels in the gun during firing.

FIG. 6 is a front elevation or muzzle end view of the gun more clearly showing the barrel retainer fulcrum plate for the forward ends of the barrels, and the removable interlock means between the barrel retainer fulcrum plate and the muzzle ends of the gun barrels.

FIG. 7 is a transverse sectional view taken about on line 7-7 in FIG. 1, looking in the direction of the arrows, with the recoil packs omitted, also omitting three of the rafmmer-ejector slides and firing pin mechanisms.

FIG. 8 is a rear end elevation view of the rear or breech end of the gun shown in FIG. 1.

As mentioned previously this invention is an improvement on machine guns of the Gatling gun types, examples of which are shown and described in the United States Patent to R. J. Gatling, Number 502,185, dated July 25, 1893, for Machine Gun; the patent to H. M. Otto, Number 2,849,921, dated September 2, 1958, for Gatling Gun; and the patent to S. Altschuler et al., Number 3,143,922, dated August 11, 1964, for Vane Type Rotary Motor for Guns (ofthe Gatling type).

Since the invention does not relate to the mounting and recoil features of the gun, nor particularly to the means for rotating the barrels about the common or central gun axis, nor the specific firing pinretraction and release mechanism, the specific details of these mechanisms may be conventional, as shown, and/or described in the above noted patents, they are not specifically shownA or described in connection with this invention, andform no important par-t thereof.

Referring to the drawings, and more particularly to FIGS. l to 3, the reference numeral 1 denotes a machine gun of the Gatling type generally, comprising a rear or breech end 2 and a front or muzzle end 3, having suitable swivel mounting or support means (not shown), and

including recoil packs or cylinders 4 for absorbing recoil The barrels 5 are notched at 9 to receive the peripheral` portion of a notched retainer or lockingl plate which is preferably held against rotation relative to the ends of the barrels 5 by a spring clip 11, as shown, suitably seated in opposite notches (notv shown), in the fulcrum plate 7, providing a releasable interlock between muzzle ends of the barrels 5 and the locking plate 7. Thel plate 7 has arcuate recesses 7a in its periphery to permit removal of the plates 7 (and 10) from the muzzle ends of the barrels 5 when the spring clip 11 is compressed and the retainer or locking plate 10 is rotated to displace the circumferentially spaced peripheral locking portions 10a from the notches 9 in the ends of the barrels, the inwardly curved or arcuate notch portions 10b inthe plate 10 being sufficient in radiusl to pass or remove the ends of the barrel when the plate 10 is turned and removed, thus freeing the muzzleends of the barrels when the plate 7 is removed. The'notches 9`in the ends of the barrels and the peripheral portions 10a may be closely fitted to assist in resisting rotation of the barrels on their individual axes due to rotational torque when the rounds are fired yet permitting a quick disconnect between the several'barrels at their muzzle ends, substantially without the use of special tools, wrenches, etc. Thisarrangement whileretaining the muzzle ends of the barrels 5 in radially andY circumferentially spaced relation toeach other also provides fory predetermined limited radial displacement of the chambered or breech ends of the `barrels in the rear end of the (Gatling) gun structure.

The rear or breech end 2 of the gun- 1 comprises a substantially cylindrical casing or shell indicated generally at 12, havingv the recoil packs or cylinders 4 fixed or mounted thereon, carryingy the slidable gun mounting recoil plungers 13 to which the gun support means` or stand (not shown) may be pivoted at 13a.4

The main casing or shell 12- is, of course, relatively stationary and has a rear closure plate 15 which is interlocked with theshell 12 and removablyl mounted, being heldin place by a channel clamping ring or band 16, contracted by a suitable expandable clamp means such as 17, shown in FIG. 6.

The plate 15, as seenin FIG. l, is suitably apertured at 15a in its center and rigidly supports a fixed concentric rotor supporting rod or shaft 18 which is keyed and pinned by the key and pin members 19 and 2f).

The shaft or rod 18 as seen in FIGS. 1 and 4 extends centrally forward through the casing 12 and carries an inner barrel camming plate 21 which is fixed or welded thereto at 22, forming the inner radial camming means for the barrels 5. The front end of the casing or shell 12 carries, in interlocked (removable) relation, an outer radial (barrel) camming plate or` annulus 23, held in place by a preferably removable circular channel clamping ring or band 24', retained by the contractable clamp means 17.

Also keyed on the shaft or axle 18 adjacent the rear closure plate 15 is flanged thrust bearing 25, retained in place by a pin or screw 25a, on which is journalled a spur drive gear 26 for rotating the rotor 27 and firing pin spring retainer pla-te 28, the rotor preferably being driven by the gear 26 through a suitable notched or spline interlock (not shown).

The drive gear 26' may be suitably driven by a meshing cranked gear (not shown), as in old conventional Gatling guns, or by a suitable electric motor drive means, the particular drive means not being important to the invention is not illustrated.

The front end of the rotor 27 is suitably journalled on the fixed shaft or rod 18 on a sleeve bearing 29 and the bearing sleeve 25a of the thrust bearing 25.

Reference being made particularly to FIGS. 1 and 5, the front end of the rotor 27 is formed with an annular recess 30, providing the rotor 27 with an annular abutment face, or round back up wall 31 which is perpendicular to the axis of rotation of the rotor and a concentric circular enlarged radially slotted head portion or annular flange 32 in which is formed the six radial slots or openings 33, best seen in FIG. 5, for receiving the'breech or chambered ends of the six rifle barrels 5, each barrel having a round receiving chamber 34 therein.

The radial slots or somewhat elongated openings 33'Yin the rotor head 32 are each formed with an annular channell or groove-35 therein for receiving the thrust flanges 36.'

which project outwardly from the opposite sides of the breech ends of the barrels into these grooves 35 for transferring barrel thrust during firing to the rotor 27.

With the barrels locked in position as shown against individual rotative torque (for instance by the locking plate 10 as seen in FIG. 6) the thrust flanges 36 on the breechI ends of the barrels are interrupted at 36A at the opposite sides of the barrels, perpendicular to the longitudinal axes of the slots 33, thus permitting removal of the barrels from the rotor head 32 when they are released at their frontl ends, rotated and withdrawn.

Referring to FIGS. 1, 4, 5 and 6 it will be observed that' as the rotor 27 rotates the radial slots 33 infthe'head 32 thereof carry the six barrels successively around the axis of the gun between the inner and outer xed or stationaryv camming means 21 and 23, thus camming the chambered barrel ends outwardly, as shownin the lower half of FIG.

1 to receive the cartridges or rounds from the feedingmeans (not shown), and as the rotor rotates, the cartridges are rammed home into the chambers 34, by the ramming and ejector means, indicated at 37 which is reciprocal in the guideways kor channels 38 shown-in FIG. 7, the rotor having channels 39 to accommodate the rounds. Asthe rotor 27 continues to rotate, and after each round is rammed home into its chamber in its barrel the rear ends of barrels are cammed radially inward in the radial slots 33 by the two stationary cam mem-bers 23 and 21 to rnove the rear ends of the rounds radially inward into position in front of the radial back up wall 31 of the rotor, with the primer of the round concentrically positionedy in front of the tiring pin 40 for that barrel.

The round is thus held or backed up while chambered in the barrel by the abutment wall 31 of the rotor 27 during firing. The firing pin is retracted by a cam or inclinedv plane 41 carried in a removable closure plate 42 which is fixed in an opening in the casing or shell 12, somewhat after the manner shown in FIG. 3 so that as the barrel is rotated to its firing position each firing pin actuating abutment or lug drops off of the high end of the cam 41 and is projected forward by its compression spring 40a tol strike the primer of the chambered round. They firing pins have radial projections 43 which engage the cam 41 successively as the rotor 27 rotates the 'barrels into the firing positions.

After each round is fired the continued rotation of the rotor 27 and barrels 5 cause the barrels to be cammed outward radially by the stationary cam means 21 (and 23) thus moving the rear ends ofthe rounds and barrels radially `outward away from the back up annual perpendicular wall 31 of the rotor to engage the annular channels in the rear ends of the rounds with the ejector clips or springs 44 on the rammer-ejector members 37.

The front end 32 of the rotor 27 is journalled in the casing 12 on rollers 45 to insure concentric rotation of the rotor in the casing and resist lateral displacement of the front end of the rotor by the cams 21 and 23 during rotation of the barrels around the central axis yof the gun.

The rammer and ejector slide members 37 are moved forward and back by a camming action lbetween the slides 37 and shell or casing 12, best seen in FIG; l.

The casing 12 is provided with an annular oblique camming channel 46 receiving rollers 47 which are carried on lateral stub shafts or axles 48 projecting radially outward from the rear ends of the rammer-ejector slides 37. As the rotor rotates lthe `barrels 5 from tiring and round 4ejector engaging positions and the breech ends of the barrels are successively cammed radially outward, out of the Wayof the wall 31 the annular oblique cam slot 46 retracts the rammer-ejectors to finally completely withdraw the expended rounds from the gun barrels. Each rammer 37, by this time is approaching the position as shown in connection with the lower barrel 5 in FIG. 1. The spent rounds, as the barrels rotatein a planetary motion around the* gun axis, are ejected from the rotor 27 and out of the casing 12 andthe round feeding means successively feeds fresh rounds into the channels in the rotor, for 'instance somewhat in the manner shown in FIG. l of the R. I. Gatling patent, previously `referred to.

It should be noted inthe sectional view in FIG. 4 that the barrels 5 are in firing position in front of the back up wall of the rotor for only a relatively small segment of the rotation of the rotor, about as indicated by the arc A in FIG. 4, ascompared to the feeding ramming and spent round withdrawal and shellejection cycles.

. Should` it be desired lto support the front ends of the barrels more rigidly against lateral displacement relative to the central axis of the main supporting casing or shell 12 (axis of the gun) several conventional methods may be employed. One method or means that can be used is to rigidly secure one end of a barrel enclosing cylindrical casing to the shell 12, or to the outer barrel camming plate 23 extending forwardlyto Venclose the barrels 5 in concentric relation, in which this enclosing casing has a roller bearing race at its forward `or outer end engaging and supporting the periphery of the circular muzzle ful- `crurn plate 7 in concentric relation to the axis of the gun, While another supporting `means for the muzzle ends of thelbarrels against lateral `displacement to the gun axis thatzmay be employed might comprise extending the shaft orrod 18 forward to thelback of the fulcrum plate 7 concentric to the gun axis, and providing the rear of the fulcrum plate `7 with a concentric sleeve bearing receiving the -outer end of `theextension of the rod or shaft 18. The latter would'also provide for quick removal and changing of the gun barrels.

- Since these suggestions for rigidly supporting the muzzle end of the gun relativeto the rear or breech end do not form a part of the present invention they are neither illustrated nor claimed.

For purposes of exemplilcation a particular embodiment of the invention has been shown and described to the best understanding thereof. However, it will be apparent that slight changes and modifications in the arrangement and construction of the parts thereof may be resorted to without departing fromthe true spirit and scope of the invention yas defined in the accompanying claims.

I claim:

1. In a multibarrel machine gun of the Gatling gun type, a casing having a longitudinal axis, a rotor journalled within said casing on said axis having an annular cartridge abutment back up wall perpendicular to said axis and a forwardly spaced outwardly extending annular flange formed with a plurality of circumferentially radial slots therein extending therethrough within the periphery of" said head, said slots extending outward beyond the periphery of said rotor abutment back up wall, a plurality of gun barrels each having a chambered breech end slidable radially inward `and outward between the opposite ends of said radial slots, means slidably interlocking said breech ends in said radial slots against relative axial barrel movement, fixed annular cam means carried by said casing engaging and successively camming said breech ends of said barrels inwardly in said radial slots during a predetermined minor degree of rotation of said rotor in front of said abutment back up wall, and successively camming said breech ends of said barrels outwardly beyond `the periphery of said back up abutment wall during rotation of said rotor through an addition predetermined minor degree of rotation, movable means on said rotor for receiving and feeding cartridges into said chambered breech ends when Said breech ends are cammed outwardly, spring projected ring pin means carried by said rotor, for concentric alignment with said chambered barrel breech ends` while cammed inward in front of said abutment back up wall relatively fixed tiring pin retracting and release cam means carried fixed on said casing for camming engagement with and release of said firing pin mea-ns during rotation of said rotor While each of said barrels is in said inwardly cammed position, and fulcrum means connecting said muzzle ends of said barrels together for outward and inward radial movement of said chambered breech ends during rotation in a planetary motion of said barrels around said longitudinal axis.

2. In a machine gun of the Gatling gun type, a barrel supporting casing having a central axis, a rotor rotatably journalled within said casing on said axis having a concentric cartridge rear end abutment back up wall perpendicular to said axis and a forwardly spaced outwardly projecting annular flanged head having a plurality of circumferentially spaced radial slots therein extending outwardly beyond the periphery of said rotor back up abutment wall, a plurality of gun barrels, one for each radial slot, circumferentially spaced and rotatable by said rotor around said axis in substantially parallel relation to each other, said barrels extending forwardly from said casing, each having a front end and a cartridge chambered rear end, slidable radially inward and outward in each of said radial slots between the inner and outer ends of said slots, means interlocking said barrel rear ends in said radial slots against relative axial movement, fixed annular camming means adjacent said flanged head for successively camming each of said barrel rear ends inwardly in said slots during a predetermined degree of rotation of said rotor, to move said chambered barrel rear ends inwardly in front of -said rotor, abutment back up wall to back up each chambered round in said barrel rear ends and successively camming said barrel rear ends outwardly in said radial slots to move each chambered round rear end therein, outwardly beyond the periphery of said rotor abutment back up wall during a subsequent degree of rotation of said rotor, firing pin means carried by said rotor for firing eachof said rounds during rotation of said rotor while said barrel rear ends yare cammed inwardly in front of said abutment back up wall to form an abutment for each chambered round in said barrel rear ends, round ejector and injector means rotatable about said axis with said rotor for withdrawing spent rounds from said barrel rear ends and injecting fresh rounds into said chambered rear ends when said rear ends are cammed outwardly by said camming means beyond the periphery of said annular perpendicular abutment back up Wall during rotation of said rotor about said axis, and means supporting the front ends of said barrels together for independent limited radial swinging movement toward and away from said 7, axis during rotation ina planetary motion thereofv around saidaxis by said rotor.

3. In` al machine gun of the Gatlingtype, an annular supporting casing having acentral axis, a plurality of gun barrels having round cartridgey chambered rear ends for receiving rounds therein, means for rotating ina planetary motion said` barrels in substantially parallel relation laround saidvaxis, annular cam means -fixed relativeto said c-asing for successively camming said barrel rear endsinwardly into firing position and outwardly into round ejecting and' fresh round loading positions during rotation, in a planetary motion, of said barrelsaround said axis, round back up abutment means disposed in spaced relation behind said chambered rear ends perpendicular to said axis for backing up chambered rounds in said barrel rear ends when each barrel rear end is cammed' inwardly toward said centralaxis, said abutment means disposedy to be out of round` back up relation when said barrel rear ends are cammed outwardly, means for ringsaid rounds while inr said chambered barrel rear ends while said rear ends are. infinwardly cammed positions, means carried by said rotor for ejecting spent rounds from and injecting fresh rounds into s-aid barrel re-ar ends while said rear ends are cammed outwardly during rotation of said' barrels in a planetary motion around said central axis, and means connecting the muzzle ends of said barrels together for limited fulcrum swinging movement as said barrel rear ends are cammed inwardly and outwardly.

4. In a machine gun of the Gatling type, a supporting casing having a central axis, a supporting shaft concentrically fixed in said casing against rotation, a rotor journalled on said shaft havingl an elongated cylindrical body formed with a plurality of circumferentially spaced parallel round receiving, ramming, and retracting recesses invtheperiphery thereof and formed with a circular concentric roundbackup abutment wall adjacent its front end extending perpendicular to said axis havinga diameter less than thediameter on. said rotor at the bottom of said round receivingrecesses, `a circular radially slotted flange xed. to said rotor in forwardly spaced concentric relation thereto havinga gun barrel rear end receiving slot therein extending radially outward from each ofl said round receiving recesses for slidably receiving said chambered rear. end of gun barreltherein, a plurality of gun barrels, each having a muzzle end and a chambered rear end slidably interlocked n-each yof said radial slots for radial in and out movements during rotation of said rotor, relatively stationary barrel camming means fixed relative to said. casing inforward-.relationto saidfradially slotted fiange, comprising concentric inner and outer radially spaced annular `camrning members forming an annular barrel camming slot therebetween` receiving said chambered barrelJ rear ends therethrough for camniing said chamberedbarrel ends inwardly andoutwardly during rotation of said rotor on said shaft, firing .pin means for each barrelV carried byisaid rotor for registration with the center of each barrel when cammed inwardly in said radial slots by said outer cam4 member including means to explode a round-chambered in said barrel when cammed inwardly, said round back up, abutment wall being disposed to back up the rear ends offrounds in said barrels during firing thereof while said barrels areA cammed inwardly by said -outer cam member to dispose the rounds in front ofy the firing pins of said fring'pin means, said Iabutment wall having a smaller radius than the radius from the axis to the barrels whencammed outwardly to dispose the periphery thereof out of axial alignment with the chambered rounds in said barrels when said barrels are cammed outwardly by said inner camming member, topermit injection and ramming home of said rounds into and extractionof said rounds from said chambered barrel rear ends while said barrels are cammed outwardly, round ramming and extractor Imeans reciprocatively slidable in each of said round receiving recesses in said rotor for receivingv and ramming rounds into thevchambered rear ends of saidv barrels while said' barrels are. in outwardly cammed positions prior tov tiring, andl extracting'v said'spend rounds from said chambered barrel ends after tiring, while said barrels are cammed outwardly andl cam means on said casing for reciprocating said rammingand ejector means forwardly andbackwardly duringy each rotation of thel rotor.

5. In a .multibarrel machine gunof the Gatling type a supporting shaft having a central axis, a plurality of gun barrels having integral chambered breech ends, and muzzle ends pivoted togetherv ,for individual radially swinging toward and away from said central axis, means for rotating said barrels in a planetaryl motion around said central axis between radially outward circumferentially spaced predetermined fixed round loading, ramming, shell extracting and radially inward firing positions, said loading, ramming. and extracting positions disposed at one predetermined radial distance from said axis, and said tiring position disposed at a predetermined lesser radial distance from said axis, annular camming means engaging said barrel breech ends successively camming said breech ends toswing said'barrels/inwardly into said tiring position, and radially outwardly into said, ejection, loading and ramming positions during rotation of said barrelsl in aplanetary motionaround said axis means rotatable around said axis with said barrels fory successivelyy firing rounds invsaid chambered barrel breech;

ends when said barrel breech endsl are cammedand swing said barrels inwardly in said tiring position, andy means rotatable around said axis with said barrels for successively withdrawing spend rounds from saidlA cham-- bered barrel breech ends when. said barrels are: swung outwardly in said ejecting position-and-finserting and ramming fresh rounds successively into said barrel breech: ends, when said barrels are in said` loading and ramming positions respectively during rotation of said barrels in a planetary motion around said axis, including back up' abutment -means disposedi behind-saidbarrel breech ends: and positioned for successively backing up rounds in said? barrels duringsaid rotation of` said barrels in a planetary, motion around saidaxiswhile said breech ends arercammed inwardly to swing said. barrels into saidringposi tion.

6. A machine gun of the Gatling type asset. forth. invclaim 5, in` which said back up abutment means com prisesan annular abutment wall perpendicular to said axis;

rotatable concentrically aroundsaid axis with` said cham-- bered barrel breech ends,.positioned for backing up each round into each of said chambered breechends only when said breech ends are cammed inwardly in said-'firing position, invwhichthe periphery of said abutment wall` is. disposed radially inwardly out of said back up relationvto said rounds while said barrel breech endsl are/cammed radially outwardly into said round extracting, loadingandr ramming positions.

7. In a multibarrel machinev gun of t-hef Gatling: type', a supporting shaft'having aycentral axis, a plurality ofgun barrels having chambered breech ends and muzzleends, means for rotating said barrels in a planetaryf motion around said central axisbetween circmnferentially spaced: predetermined fixed round loading, ra1nming, iiringfandA shell extracting positions, vsaid loading,tramming, and' extracting positions of said breechends disposed atene-pre'- determined radial distance from said axis, and said firingi position of said breech ends disposed at a predetermined lesser radial distance from saidl axis, annular camming means engaging said breech ends successively, camming. said breec-h ends inwardlyinto said firing position, andl outwardly into said ejection, loading, and ramming positions during rotation of said barrels in a planetary, motion around said axis, means rotatable aroundl said axisV with said barrels for successively tiring rounds in said chambered barrel breech ends when said barrel'breech ends are cammedl inwardlyy insaid firing position, and ymeansrotatable around said axis with said barrels for successively withdrawing spent rounds from the chambered barrel breech ends when in said ejecting position and inserting and ramming fresh rounds successively into said barrel breech ends, when said barrel breech ends are in` said loading and ramming positions respectively during rotation of said barrels in a planetary motion around said axis, backup abutment means disposed behind said barrel breech ends for successively backing up said rounds in said barrels during rotation of said barrels in a planetary motion around said axis when said breech ends are cammed inwardly to swing said barrels into said ring position, said backup abutment means comprising an annular abutment wall perpendicular to said axis and rotatable concentrically around said axis with said chambered breech ends positioned for backing up each round in each of said chambered breech ends only when said breech ends are cammed inwardly into ring positions, in which said abutment wall is disposed radially inward out of said backup relation to said rounds w-hile said barrel breech ends are cammed outwardly in said round extracting, loading and ramming positions, and means connecting the muzzle ends of the barrels together for vlimited inwardly and outwardly swinging movement of said barrels during rotation of said barrels in said planetary motion around said axis, between said tiring and shell extracting, loading, and ramrning positions References Cited UNITED STATES PATENTS 1,330,776 2/1920 Ardouin. 2,959,106 11/1960 OBrien 89-126 2,971,440 2/1961 OBrien 89-12 X BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

S. C. BENTLEY, Assistant Examiner. 

3. IN A MACHINE GUN OF THE GATLING TYPE, AN ANNULAR SUPPORTING CASING HAVING A CENTRAL AXIS, A PLURALITY OF GUN BARRELS HAVING ROUND CARTRIDGE CHAMBERED REAR ENDS FOR RECEIVING ROUNDS THEREIN, MEANS FOR ROTATING IN A PLANETARY MOTION SAID BARRELS IN SUBSTANTIALLY PARALLEL RELATION AROUND SAID AXIS, ANNULAR CAM MEANS FIXED RELATIVE TO SAID CASING FOR SUCCESSIVELY CAMMING SAID BARREL REAR ENDS INWARDLY INTO FIRING POSITION AND OUTWARDLY INTO ROUND EJECTING AND FRESH ROUND LOADING POSITIONS DURING ROTATION, IN A PLANETARY MOTION, OF SAID BARRELS AROUND SAID AXIS, ROUND BACK UP ABUTMENT MEANS DISPOSED IN SPACED RELATION BEHIND SAID CHAMBERED REAR ENDS PERPENDICULAR TO SAID AXIS FOR BACKING UP CHAMBERED ROUNDS IN SAID BARREL REAR ENDS WHEN EACH BARREL REAR END IS CAMMED INWARDLY TOWARD SAID CENTAL AXIS, SAID ABUTMENT MEANS DISPOSED TO BE OUT OF ROUND BACK UP RELATION WHEN SAID BARREL REAR ENDS ARE CAMMED OUTWARDLY, MEANS FOR FIRING SAID ROUNDS WHILE IN SAID CHAMBERED BARREL REAR ENDS WHILE SAID REAR ENDS ARE IN INWARDLY CAMMED POSITIONS, MEANS CARRIED BY SAID ROTOR FOR EJECTING SPENT ROUNDS FROM AND INJECTING FRESH ROUNDS INTO SAID BARREL REAR ENDS WHILE SAID REAR ENDS ARE CAMMED OUTWARDLY DURING ROTATION OF SAID BARRELS IN A PLANETARY MOTION AROUND SAID CENTRAL AXIS, AND MEANS CONNECTING THE MUZZLE ENDS OF SAID BARRELS TOGETHER FOR LIMITED FULCRUM SWINGING MOVEMENT AS SAID BARREL REAR ENDS ARE CAMMED INWARDLY AND OUTWARDLY. 